function isEmail(str) {
  // are regular expressions supported?
  var supported = 0;
  if (window.RegExp) {
    var tempStr = "a";
    var tempReg = new RegExp(tempStr);
    if (tempReg.test(tempStr)) supported = 1;
  }
  if (!supported) 
    return (str.indexOf(".") > 2) && (str.indexOf("@") > 0);
  var r1 = new RegExp("(@.*@)|(\\.\\.)|(@\\.)|(^\\.)");
  var r2 = new RegExp("^.+\\@(\\[?)[a-zA-Z0-9\\-\\.]+\\.([a-zA-Z]{2,3}|[0-9]{1,3})(\\]?)$");
  return (!r1.test(str) && r2.test(str));
}
function doesNotXist(userEntry)
{
    if (userEntry==null || userEntry==" " || userEntry=="") {
		return true;
	} else {
		return false;
	} 
}
   
   
function FormCheck()
{
    var message="";
    var erreurs=0;

    if(doesNotXist(document.LEDsLIGHT.sender_name.value)) {
        message+="Gelieve uw naam in te vullen\n";
        erreurs+=1;
    }	
    if(!isEmail(document.LEDsLIGHT.sender_email.value)) {
	    message+="Gelieve een geldig e-mailadres in te vullen\n";
        erreurs+=1;
    }
	
	if(erreurs>3) {
		alert('Gelieve het formulier in te vullen alvorens het te versturen aub');
		return false;
    } else if(message!="") {
        alert(message);
	    return false;
    } else {
	    document.LEDsLIGHT.submit();
	    return true;
    }
}